With the development of communication technologies, more and more new technologies emerge, and wideband code division multiple access (WCDMA) is a third generation radio communication system which is most widely applied at present. How to evolve a WCDMA system to satisfy users' requirements for high speed uplink and downlink data transmission is the most important research work in the field of radio communications. Since R5, a series of important technologies are introduced into WCDMA to improve an uplink and downlink data transmission rate: high speed downlink packet access (HSDPA), high speed uplink packet access (HSUPA), multiple-input multiple-output (MIMO), and 64-phase quadrature amplitude modulation (QAM).
At present, MIMO in high speed data access (High Speed Packet Access, HSPA) is dual-transmitting antenna MIMO. A scheduled UE has a maximum of two transport blocks, namely, a primary transport block and a secondary transport block, where the secondary transport block is for optional transmission. The two transport blocks undergo a processing process of a transport channel, spectrum spreading, scrambling, and precoding operation, and then are sent together with a common pilot channel (CPICH) on two transmitting antennas, thereby cancelling interference between the antennas by precoding. A base station (NodeB) needs to notify a user equipment (UE) of control information of a high speed physical downlink shared channel (HS-PDSCH), so that the UE receives the HS-PDSCH. The control information includes a code channel number, the number of code channels, a modulation scheme, precoding, the size and the number of transport blocks, redundancy and constellation version, and the like. Such control information is borne over a high speed shared control channel (HS-SCCH). A downlink MIMO control channel uses an HS-SCCH type (type) 3 format, and different numbers of data blocks correspond to different formats.
An HS-SCCH type 3 format includes the following information in cases of one data block (a single code word for short):
channelization-code-set information (Channelization-code-set information): seven bits (bit) in total, which respectively are: xccs,1, xccs,2, . . . , xccs,7;
modulation and data block information (Modulation scheme and number of transport blocks information): three bits in total, which respectively are: xms,1, xms,2, xms,3;
precoding weight information (Precoding weight information): two bits in total, which respectively are: xpwipb,1, xpwipb,2;
transport-block size information (Transport-block size information): six bits in total, which respectively are: xtbspb,1, xtbspb,2, . . . , xtbspb,6;
hybrid automatic repeat request process information ((Hybrid Automatic Repeat Request, Hybrid-ARQ) process information): four bits in total, which respectively are: xhap,1, xhap,2, . . . , xhap,4;
redundancy and constellation version (Redundancy and constellation version): two bits in total, which respectively are: xrvpb,1, xrvpb,2; and
UE identity (UE identity): 16 bits in total, which respectively are: xue,1, xue,2, . . . , xue,16.
An HS-SCCH type 3 format includes the following information in cases of two data blocks (a dual-code word for short):
channelization-code-set information (Channelization-code-set information): seven bits in total, which respectively are: xccs,1, xccs,2, . . . , xccs,7;
modulation and data block information (Modulation scheme and number of transport blocks information): three bits in total, which respectively are: xms,1, xms,2, xms,3;
precoding weight information (Precoding weight information for the primary transport block): two bits in total, which respectively are: xpwipb,1, xpwipb,2;
transport-block size information for the primary transport block (Transport-block size information for the primary transport block): six bits in total, which respectively are: xtbspb,1, xtbspb,2, . . . , xtbspb,6;
transport-block size information for the secondary transport block (Transport-block size information for the secondary transport block): six bits in total, which respectively are: xtbssb,1, xtbssb,2, . . . , xtbssb,6;
hybrid automatic repeat request process information (Hybrid-ARQ process information): four bits in total, which respectively are: xhap,1, xhap,2, . . . , xhap,4;
redundancy and constellation version for the primary transport block (Redundancy and constellation version for the primary transport block): two bits in total, which respectively are: xrvpb,1, xrvpb,2;
redundancy and constellation version for the secondary transport block (Redundancy and constellation version for the secondary transport block): two bits in total, which respectively are: xrvsb,1, xrvsb,2; and
UE identity (UE identity): 16 bits in total, which respectively are: xue,1, xue,2, . . . , xue,16.
The channelization-code-set information, modulation and data block information, and precoding weight information are sent in time slot 1, and are referred to as part 1 (Part1) of control information; the remaining ones are sent in time slot 2 and time slot 3, and are referred to as part 2 (part2) of the control information.
After the research of several versions, the improving the transmission efficiency of a radio channel reaches a bottleneck. In order to satisfy users' requirements and to meet a challenge of other technologies, it is considered to introduce multiple-antenna (more than 2) MIMO operation into a down link in a WCDMA system, thereby further improving cell throughput. In multiple-antenna MIMO, one data block may be divided into multiple layers by layer mapping, where different precoding is performed on data of each layer, and then the data is sent by using spatially separated antennas, thereby further obtaining a gain of space diversity. Layer number information in the multiple-antenna MIMO needs to be notified by a base station (NodeB) to a user equipment (UE), which, however, cannot be implemented in the prior art.